Electric apparatus



March 26, 1929. w. E.- PAUL ELECTRIC APPARATUS Filed sept. 25, 1925 u, Vm z E m w Ilm n m t 6 x Mil il@ f A .fm u W H d f U l2 .3 5

Patented Mar.A 26, 1929.

i UNITED STATES PATENT oFFlcE.

WILLIAM E. PAUL, OF SCHENECTADY, NEW YORK, ASSIGNOB. TO GENERAL ELECTRICCOMPANY, A. CORPORATION F NEW YORK.

ELECTRIC APPARATUS.

Application iiled September 23, 1925. Serial No. 58,156.

My invention relates to electric apparatus of the kind which includes anenclosing casing through the top of whichV extend conductors supportedin insulator bushings. It

is an object of my invention to provide ap- Aparatus of this characterhaving improved means for dissipating the heat generated 1n theconductor by the current carried thereby.

My invention will be better understood 1d from the following descriptiontaken in connection with the accompanying drawing, and its scope will bepointed out in the appended claims.

Referring to the drawing, Fig. 1 is a side elevation with parts shown insection of an electric switch embodying my invention; and Fig. 2 is across section taken on line 2-2 of Fig. 1.

On the drawing I have shown at l thetank 2o of an oil switch through thecover 2 of which extends the insulator bushings 3 and the operating rod4 carrying the bridge 5. The bushings are shown mounted iin the cover inthe customary manner by being cemented in the ring 6 which is bolted tothe cover. y In switches of this type as ordinarily constructed theterminal studs which pass through the insulator bushings and by whichthe circuit connections are made with the stationary contacts of theswitch are solid. Under conditions of heavy loadexcessive heating of thestuds sometimes occurs, particularly in their central portions wherebeing surrounded by the bushing the loss of heat is the least. In

accordance with my invention I have made the stud 8 hollow and have madeprovision i for the passage of a Ventilating current into and out of thestud. In the lower end of the hollow stud 8 is secured the stationaryconof the tube. Near the top of the tube is shown a deflecting ring 14.

Due to the heating of the air between the tube and the walls of the studa natural draft of air is produced, the warm air outside of the tubearising while cooler air flows down through the tube to replace it.Under cerf tain circumstances it may be desirable tohave ajorcedcirculation of air or other cooling medium in which case suitable meansmay be employed .to induce the desired'circulation.

While I have chosenv to illustrate my invention :is applied to an oilswitch it is not limited to such but is applicable to various other AbyLetters Patent of the United States, is:

1. In electric apparatus having an enclos- 7o ing casing, an insulatorbushing in the top thereof, ahollow terminal stud in the bushing, and amember extending longitudinally in the stud dividing the opening thereininto an inner and an outer passageway, said passageways being incommunication with each other at their lower ends and being open to theatmosphere at their upper ends.

2. In electric apparatus having an enclosing casing, an insulatorbushing in the top thereof, a hollow terminal stud in the bushing, and alongitudinally extending tube in the stud spaced from the walls thereofto vform inner and outer passages which connect with each other at theirlower ends and whichopen to the atmosphere at their upper'ends wherebycooling air may enter the stud through the tube and escape between thetube and the walls of the stud. Y

3. Electric apparatus comprising current ,carrying members immersed ininsulating liquid, an enclosing casing therefor, an insulator bushingextending through the top of the casing, a hollow terminal stud in saidbushing secured at its lower end to one of said 95 members and open atits upper end, a tube open at its upper end extending down into saidhollow stud and means for spacing the tube at its sides and lower endfrom the'stud whereby the stud is cooled by a naturalcirculation ofair'over its inner surface.

4. An electric switch comprising relatively movable contacts separablein an insulating liquid, an enclosing veesel therefor, an insulatorbushing extending through the 'top of the vessel, a hollow terminal studin said .5 bushingn secured utits lower end to one of said contacts` andopen at''tsy upper end, a tube open at its upper end extending down into'said hollow stud, means for SPelCDg the tube at its sides und lower endfrom the stud .and a deflector on the tube abovethe upper. end of 10thelstud.

In Witness whereof, I have hereunto set my hund this QZnddny ofSeptember, 1925.y

` WILLIAM E.

